This application claims priority to French Application No. FR P 9902601 filed on Mar. 1, 1999, and incorporates that application herein by reference.
The present invention regards man made filaments. More specifically the present invention regards method and apparatus for producing multi-segment filaments, multi-segment filaments themselves, and textiles formed with multi-segmented filaments.
Multi-segmented filaments are man made tendrils made from polymers. Numerous processes are presently known for the production of these multi-segmented filaments or fibers. Some of these known procedures extrude the filaments directly from the raw materials while others utilize recycled materials, such as non-woven textile surfaces, to create the multi-segmented filaments. In one known production process, thermoplastic polymer materials are co-extruded through divided spinning die openings to form the desired multi-segment filament forms. Such a process, however, results in mono-filaments, which suffer from numerous restrictions and disadvantages, being formed. For example, it is difficult to separate the multi-segment mono-filaments into more basic elementary filaments. If required, machines are utilized to attempt this separation. Unfortunately, these machines, which are not always successful in separating the filaments, are cumbersome as they must be able to develop significant concentrated forces in order to carry out the separation. In fact, in some circumstances, such as when the elementary filaments are formed from the same polymer or from chemically compatible polymers, their separation back into their original state is impossible to carry out. Similarly, when materials in their miscible state are used to create multi-segmented filaments, they, too, may also be impossible to separate into a filament state.
In addition, known technology only offers a limited number of shapes and titers for the manufacture of multi-segmented filaments due to: the complexity of the feed circulations in the dies; the low limit conditions of spinning and extrusion for the fine-titer filaments or fibers; the physical impossibilities that result from co-extrusion; and the exorbitant costs associated with manufacturing the required spinning dies.
Further to these obstacles, it is also not possible with current technologies, to achieve complex external cross-sections having clear outlines such as edges and notches. Due to the rheological properties of polymers these edges and notches fade during this known co-extrusion manufacturing process.
Multi-segmented filaments and method and apparatus for producing multi-segmented filaments are provided. In one embodiment a first polymer material is passed into a spinning die, the first polymer material and the spinning die being maintained under predetermined rheological conditions. Next, the first polymer material is extruded through a plurality of die openings in the die, the die openings arranged in a group, the group configured to form at least two elementary filaments. Then, the two elementary filaments are connected to one another by adhesion contact to form a multi-segmented filament.
In another embodiment a die for producing multi-segmented filaments is provided. This die comprises a polymer source maintaining a polymer under predetermined rheological conditions; a die in communication with the polymer source, the die maintaining the polymer under predetermined rheological conditions; and a die plate in fluid communication with the die, the die plate defining a first group of openings, the first group of openings comprising a first opening and a second opening, the first opening and the second opening configured to form a first elementary fiber having a skin and a second elementary fiber having a skin.
In yet another alternative embodiment a multi-segmented filament is provided. This filament comprises a first elementary fiber having a skin and a second elementary fiber having a skin. In this embodiment the first elementary fiber is connected longitudinally to the second elementary fiber by adhesion of the skin of the first elementary fiber with the skin of the second elementary fiber.